On-line impedance monitoring of transformer based on inductive coupling approach

An on-line impedance monitoring method of a transformer is proposed based on two-probe inductive coupling approach. The theory behind the method is described and validated experimentally. As it does not require direct electrical contact with the transformer powered by high voltage power supply, it can be easily installed on site and most importantly, it eliminates the potential electrical hazards imposed on the personnel who set up the measurement instrumentation.